Threading attachment for multiple spindle machine



Nov. 20, 1956 3 Sheets-Shes; 1

Filed Nov. 6, 1952 Q INVENTOR ARTHUR H. JOBERT ATTORNEYS Nov. 20, 1956 A.'H. JOBERT 2,770,819

THREADING ATTACHMENT FOR MULTIPLE SPINDLE MACHINE Filed Nov. 6, 1952 3 Sheets-Sheet 2 N INVENTOR ARTHUR H. JOBERT ATTORNEY$ Nov. 20, 1956 A. H. JOBERT 2,770,819

THREADING ATTACHMENT FOR MULTIPLE SPINDLE MACHINE 3 Sheets-Sheet 3 Filed Nc'av. 6, 1952 .Q |li V Fll INVENTOR H. JOBERT BY 5 a a z ARTHUR ATTORNEYS United States Patent ATTACHMENT FOR MULTIPLE SPINDLE MACHINE Arthur H lobert, New Britain, Conn., assignor to The New Britain Machine Company, New Britain, Conn., a corporation of Connecticut Application November 6, 1952, Serial No. 319,011

23 Claims. (Cl. -89) THREADING This invention relates to automatic multiple-spindle metal-working machines, and more particularly to the means for driving or actuating auxiliary attachments common to this type of machine. Such attachments may include independently operated drilling and reaming spindles, tapping and threading spindles, work inserters, pick-01f spindles, or any other type of attachment requirirli g1 motion parallel to but independent of the main tool s1 e.

"It is an object of the invention to provide improved mechanism of the character indicated.

Another object is to provide a simple and compact aux iliary attachment-operating mechanism which can be removed and relocated on the same machine (or on other machines) to suit different job set-ups, all with a minimum of down time.

It is another object to provide a simple universal auxiliary attachment-operating mechanism, adaptable for selective actuation of a number of different types of mechanism having different basic functions, feed cycles, etc., all with a minimum amount of required conversion time to adapt the attachment to such different applications.

It is also an object to provide an auxiliary attachmentoperating mechanism meeting the above objects and as compact and as unit-handling as possible.

A further object is to provide adjustment features in a mechanism of the character indicated with maximum accessibility to the parts requiring adjustment.

It is a specific object to provide a single auxiliary attachment-operating mechanism incorporating a stop and die-trip element in a single co-axial assembly.

Still another specific object is to provide an attachment of thecharacter indicated and incorporating a stop, as for the control of depth and shoulders, and at the same time remaining completely enclosed and protected against chip's while providing'external accessibility for stop adjustment. Other objects and various further features of novelty and invention will be pointed out or will occur to those skilled in the art from a reading of the following SPCCIfiCZ".

tion in conjunction with th accompanying drawings. In said drawings, which show, for illustrative purposes only, preferred forms of the invention:

Fig. 1 is a fragmentary view in perspective showing a multiple-spindle machine to which mechanism, incorporating features of-the invention, has been applied, said mechanism being shown operatively connected to'control a self-opening die at one station and a reamer at the next succeeding station;

Fig. 2 is a vertical sectional view taken through the gap of the machine, as in the plane 22 of Pig. 1;

Fig. 3 is a fragmentary view partly in elevation and partly in section, illustrating a set-up for a threading die, and taken substantially in planes defined by the lines 3-3 of Fig. 2;

Fig. 4 is a view similar to Fig. 3 butillustrating the viewed inthe plane 4-4 of Fig.2; and v Fig. 5 is an enlarged fragmentary view in perspective, illustrating a modification of certain elements of the mechanism of Fig. 1.

Briefly stated, my invention contemplates a simple unitary attachment comprising a plurality of longitudinally relatively movable rods, sleeves or the like, with means for simplified universal mounting of the attachment at any one of a number of stations on a particular machine, and with means for simplified inter-connection of the 'parts to each other and to various types of attachments to be actuated thereby. The mechanism may includea fully concealed stop for determining the limit for a given phase within a machine cycle, and provision is made for extreme ready accessibility to adjust the stop, regardless of the working station at which the attachment is mounted, and without requiring access within the power case of the machine.

Referring to the drawings, my invention is shown in application to a multiple-spindle machine, which may be a bar or chucking machine of the type disclosed in U. S. Patent No. 2,055,435. Such machines may include a plurality of work-supporting spindles journalled in a spindle carrier and indexible from station to station at one end of the machine. The other end of the machine may include a power case 10 joined to the Work-supporting end by a top plate 11 and by a bed or other frame means (not shown). The machine may also include a central stem 12 between the two ends of the machine and on the axis of the spindle carrier. .A multiple-station tool slide 13, which may be of the so-called Gridley type, may be slidably mounted on the stem 12 and actuated by conventional feed means including a feed-thrust plate 12. For normal turning operations, tools are fixedly mounted on the tool slide 13, and turning isaccomplished simultaneously at a plurality of work-spindle stations upon each feed and retraction cycle for the slide 13. The mechanism thus .far described is old and well knownand therefore will not be described in further detail.

For many applications, it is necessary that auxiliary attachments be carried by the tool slide 13 or that they be suspended from the top plate 11, for reciprocation longitudinally with respect to the work; and such attachments may require feeds or feed cycles which differ from the normal feed cycle of the tool slide 13 itself. Such attaclrments may include drilling and reaming spindles, work inserters, pick-off spindles, and the like, but in the form shown, I illustrate application of my invention to threading and tapping operations performed at successive stations on the tool slide 13. (For convenience, spindle stations are identified by application of appropriate ref- 1 erence numerals to the axes or centers for rotation at such stations in Fig. 2; e. g. station No.1, station No. 2 station No. 6. 1 have showna threadingdie 14, mounted for operation at afirst statiomwhichmay be station-No. 5' for the six-spindle machine presently illustrated. .Also illustratedis'a reaming-operation to be peri'ary rotary drive be imparted to the threadingand ream- 1 ing tools 14-15. For this purpose, the power case 10 may include mechanism for selectively clutching any de-' sired rotary speed to aselected 011601 more attachment spindles journalled in the power case 10. Driving and clutching mechanisms for such spindles are well known and therefore will not-bedescribed in detail. *Suffice it to say, withreference to Fig. 3, that each of the tools 14-45 is mounted onits own spindle '16 17journalled, as at 18, in thepowercase aud formed with elongatedsplines-H-so'as to permit such longitudinal feeds; as-may be required with respect to the work 20 held in;

one of the spindles 21 at the work-supporting end of the machine.

To provide an accurate axis location for the projecting cantilevered part of the spindles 1617, bearing means 22 station No. 5, and 23 at station 6, may be securely clamped to the appropriate faces of the tool slide 13. The front ends of the tool spindles 16-17 may each include a chuck 24-25 for the accommodation of the particular tool to be mounted thereon.

In accordance with the invention, I so finish the front plate 30 of the power case 10 that there is provided symmetrically between each pair of adjacent spindle bores 3132 (see Fig. l) mounting means for the accommodation of a single attachment-control device. Such mounting means may comprise a symmetrical plurality of tapped holes 33 about mounting bore 34. These parts are identified in Fig. 1 at stations at which no attachments happen to be mounted, and unused mounting means 3334 may be covered by plates 34' (see Fig. 2), as for protection against chips.

Basically, each attachment-control assembly may comprise a concentric arrangement of three longitudinally relatively displaceable and mutually supporting elements; thus, a center element or rod 35 may be nested slidably within concentric tubes 36-37. I prefer that intermediate tube 36 shall be unactuated and shall provide a frame reference within the attachment-control assembly; therefore, this intermediate tube is shown provided at the frame end with a mounting flange 38, which may be of triangular planform and secured by means of three screws 39 within the tapped mounting holes 33 (in the power case 10) for one of the mounting positions immediately adjacent station No. in the case of the threading tool 14, and for another mounting position adjacent station 6 in the case of reaming tool 15.

Aside from serving the function of providing a frame reference, the intermediate tube 36 may constitute elongated guide means for the outer or feeding tube 37. Feeding movements may be derived from cam means 40 carried within the upper part of the power case 10. Such cam means may include a follower bar 40, guided within the power case and longitudinally reciprocated by the cam means; bar 40 may carry a feed bracket or driving block 41 at the outer exposed end. A rocker arm 42 may carry a roll at its upper end in engagement with ways in the block 41, so that arm 42 may be angularly reciprocated about a fixed pivot 43, as determined by the cam program. The other end of the rocker arm 42 may pivotally carry a slide block 44 engaging bracket means 45 formed as a part of or securely attached to the outer or feed tube 37. If desired, axis alignment as between the axis of tool spindle 16 and the axis of the control mechanism may be maintained by means of a guide member 46 slidably accommodating the feed tube 37 and clamped at 47 to an axially projecting sleeve 48 of the outboard bearing 22; the guide member 46 may be positioned on either side of the bearing 22, depending on the side toward which the sleeve 48 projects, as determined by set-up requirements. Feed movement of the tube 37, in response to cam-actuated motion of rocker arm 42 may be transferred to the spindle 16 by way of a thrust yoke 49, which may be securely clamped by set-screw means 50 to the feed tube 37 and which may carry anti-friction thrustbearing means 51 for imparting thrust to the rotating spindle 16. In certain cases, as in the case of a threading operation in which it may be desired to have the tool 14 itself determine the precise instant and manner of engaging the work, it may be preferred not to clamp the yoke 49 to the feed tube 37 but rather to have the same slidably mounted or guided on the feed tube 37. For this purpose, the set screws 50 may serve to draw opposed jaws of the yoke 49 together around the feed tube 37, and a spacer screw 52 may serve to prevent a tight clamping. Of course, if the yoke 49 is merely guided and not secured to the feed tube 37, then feeding movement must be imparted by other means, and in the case of a threading operation such movement. may be imparted through a resilient connection including a preloaded spring 53 between the yoke 49 and a clamp 54 secured to the feed tube; bolt means 55 may span the clamp 54 and the yoke 49 in order to maintain the preload on spring 53.

With the mechanism thus far described, it will be seen that while the movement of the outboard bearing 22 is governed by the normal feed cycle of the Gridley slide 13, its movement in no way affects the travel of the tool spindle 16--17. The program for the tool spindles is governed entirely by means of separate cam means within the power case, actuated by way of follower 40 and arm 42 in the case of the spindle 16 (and independently by way of bar 56, pivoted arms 5757, slide block 58, and bracket 59, in the case of spindle 17). It will be understood that two separate cam means may govern the independent movements of the actuated arms 42-57, so as to effect different feeds for the separate tools at station No. 5 and station No. 6.

The inner-rod member 35 of my attachment-operating mechanism may serve as a stop or trip rod. As shown, the rod 35 includes a reduced elongated inner or back end 60 projecting into the power case 10 and terminated by adjustable stop means, such as lock nuts 61. If desired, a sleeve 62 may be set on the reduced end 60 adjacent the stop nuts 61 in order to project the effective stop limit for the rod 35 further forward, as when relatively short-stroke cam means 40 are employed. The stopping and tripping function occurs when the stop nut 61 or the sleeve 62 (depending on the set-up) strikes a fixed boss 64, constituting a positive stop contained within the intermediate tube 36. The boss 64 may be integral with the tube 36, but I have shown it merely as a sleeve, pinned at 65 to the intermediate sleeve 36 and, therefore, directly to the frame of the machine. If desired, a rubber bushing or sleeve 66 may be provided between the bracket 45 and the mounting flange 38 so as to cushion any shock occasioned on a quick return of the feed tube 37, at the termination of any particular feed cycle thereof.

To complete the description of the basic elements of my attachment, it may be stated that the forward end of the inner or trip rod 35 may be threaded, as at 67, for use with various attachments, as will more clearly appear below. The outer exposed end of the outer or feed tube 37 may also be threaded and, for protection against damage, I prefer that the thread be provided within a counterbore 68 at the end of tube 37.

The usefulness of my attachment-operating mechanism will be more apparent from the description of typical setup of the mechanism, first for operation of the threading die 14 (Fig. 3), and then for operation of the reamer 15 (Fig. 4). For the threading operation depicted in Fig. 3, it is desired quickly to bring the die 14 into operative connection with the work 20 and thereafter to allow this tool to generate its own feed, depending upon the thread characteristics and depending upon the relative rotational speed of the threading spindle 16 and of the work spindle 21. It is therefore not desired to provide any fixed longitudinal feed as long as the die is able to generate its own feed. Upon completion of a desired length of feed, which is preferably o1.v determined by reference to the frame of the machine, if. is desired to terminate threading and to retract the die 14. My attachment-operating mechanism will be seen to effect and to promote all of these functions to the desired extent and in the desired manner.

The first function of quickly bringing the tool to operative relation with the work is effected by the camderived movement of rocker arm 42 and is translated to the spindle 16 through feed tube 37, clamp 54, spring 53, and yoke 49. Once the jaws of die 14 take into the work, the die head may carry itself forward independently of any feed imparted to the spindle 16, all as deterforward movement may be traced or followed by a fork 69, riding a groove in the sleeve or outer member of the die head 14 and preferably connected to the trip rod 35. For this purpose, a special attachment may simply include an elongated nut70 having wrenchfiats 71 at the outer exposed end and having outer dimensions to fit within and to clear the bore of the feed tube 37. The nut may be threaded tight against the projecting threaded end 67 of the trip rod 35, and the nut 70 may integrally include an outwardly projecting threaded end 72' upon which the trip fork 69 may be 'adjustably clamped by nuts 73, at a location depending upon the desired limit of the threading operation. As the die 14 feeds itself upon the work,

the fork 69 will pull the trip rod 35 forward within the guide tube 36, until such time as the stop nuts 61 or sleeve 62 encounter the fixed internal stop 64.

The die 14 shown happens to be of the self-opening type, and it suffices to say that it comprises axially slidable parts with co-acting cam means 7464 on the jaws and on the external or setting sleeve, respectively. Therefore, when the rod 35 is arrested by stop 64, the setting sleeve will be stopped, and the jaws will feed themselves until the cam means 7475 allows the jaws to fly out of cutting position. The die may then stay harmlessly in a full feed-out position until such time as the basic program cam determines a retracting feed movement of the rocker arm 42. This return movement is preferably of such extent as to fully retract the die 14 and, therefore, fork 69 so that the'rear end of nut 70 will strike against the forward end of the intermediate tube or guide 36, thus arresting the rearward motion of the trip rod and of the setting sleeve. Thereafter, a slight amount of retracting motion will further retract the spindle 16 and therefore the internal die parts, including the jaws, thus resetting the jaws for the next cutting-operation.

For the reaming operation illustrated in Fig. 4, the basic employment of my attachment-operating mechanism may generally resemble that described in Fig. 3; therefore, corresponding parts have been shown with the same reference numerals. However, in operations such as the reaming operation illustrated, it is necessary to provide a positive motion for feeding the reamer into the work. Therefore, in the set-up forthe reamer 15, I have not employed spring means analogous to the spring means 53. However, bracket means 54 may still be provided on the feed tube 37 but adjustably and rigidly secured, as by means of an axially extending adjusting screw 80 to the yoke 49.

The bracket means 54 will be seen to serve a useful function when setting up the machine. Ordinarily, a rough estimate can be made for the desired axial placement of the thrust yoke 49 on the feed tube 37, but once all the parts have been assembled, it becomes neces sary to make a final minute adjustment, as to obtain a proper shoulder length or hole depth; such small adjustment will ordinarily be necessary upon initial set-up of the machine and after each tool grind. To accomplish such small adjustments, the threaded means 80 may be revolvably mounted with thrust-limiting means in the bracket 54 and threaded into the body of yoke 49; thus, when it becomes necessary to make fine axial adjustment of the tube 37 with respect to the spindle 17, a wrenchactuated movement of threaded means 80 (with bracket 54 clamped, and yoke 49 unclamped, to tube 37) may readily accomplish the necessary movement. Once a desired adjustment'has been completed, screws 50 may be tightly secured so as to clamp the yoke 49 directly on the feed tube 37. Although bracket means 54 may be positioned to the left of the yoke 49 as shown in Figs. 3 and 4, it will be appreciated that it may just as readily be located to the .right of yoke 49 in order to meet other set-up requirements.

In order to insure proper control of shoulder length and hole depth, I desire to employ my attachment-operating mechanism to provide a definite positive limit or stop *6 to. the feed. This limit may again be determined upon interception -of-.the stop nuts 61 01 sleeve 62, as thecase maybe, by the fixed internal stop 64; and to assure that this fixed stop or forward-feed limiting reference will be applied to the feed tube 37, I provide a direct connection,

as by a bushing 81 :threadedly secured at 68 to the feed tube 37, and at 67 to the trip or stop rod 35. Alock nut 82 may serve to hold a given longitudinal adjustment of the trip or stop position of rod 35 with respect to the feed tube; and, in accordance with a featureof the invention, the forward projecting end of the stop rod 35 may include wrench flats 83 projecting in the open for-convenient access. Thus, once the attachment-operating mechanism has been set up as described for control of the reamer 15, adjustment for the positive stop in relation to the feed cam may be achieved without having to enter the power case 10 and, therefore, without having to reset the stop nuts 61. The only operation necessary is the employment of two wrenches at 82 and 83, first, to -re- 7 lease the lock-nut action; second, to adjust stop rod 35 so that sleeve 62 abuts stop 64 when the cam roll of bar 56 is on the high point or final dwell of its cam; and, third, to lock the assembly in adjusted position. No further adjustment of the stop rod will be necessary until the operating cam is changed for a different set-up. From the above, it will be seen that the reamer 15 may be adjusted for shoulder length and hole depth after 'each grind by means of adjusting screw Without in any way disturbing the adjustment 8283 of the stop rod 35.

By reference to Fig. 2, it will be seen that my concentric .and unitary arrangement of attachment-operating mechanism makes possible a symmetrical employment of any particular attachment-operating mechanism with either of the tool-carrying spindles adjacent thereto. Thus, if a shop completes a run with the described set-up,

namely, with a threading tool 14 at station No. 5 and with a reamer at station No. 6, it is a relatively simple matter to change over for other tooling purposes. For example, if a subsequent set-up calls for a threading operation at station No. 4, instead of at station 5, the attachment-operating means previously described in connection with the threading die of station 5, may be left in the same position and actuated by the same rocker arm 42; the only necessary correction willbe, of course, to dismount the tool spindle 16 from the No. 5 position and to remountit, as in outboard bearing 22', at the No. 4 position. In this change-over the yoke 49 need only be swung over from its position extending to station No. 5 (as shown in Fig. 2) counterclockwise to a position (not shown) but extending toward station No. 4, as will be understood. The same shifting of parts may apply also for relocation of the spindle 17 at station No. 5, as when attachments are required at stations 4 and 5, for the location of any other attachments to be carried by the tool slide 13 and to be actuated in a feedcycle differing from that provided by the tool slide 13.

Certain set-ups require three auxiliary spindles (all of which may be at adjacent stations), and since there are only two actuating bars 40'56, two of these spindles may have to be connected in pairs to a single driving sleeve 37; thus, spindles at stations 4 and 5 or at stations 5 and 6) may be connected together depending upon which combination best suits the set-up requirements. Assuming that spindles at station No. 4 and at station No. 5 are connected as a pair, another yoke 49 may be clampedto the feed tube 37 and .project for thrusting engagement With the other adjacent spindle, namely, the spindle at tool station No. 4. The two yokes 49 then mounted-on the same feed tube may be adjacent or axially spaced from each other, depending upon the axial location and length of adjacent tools.

Fig. 5 shows that adjacent spindles 1617, which may be the spindles for adjacent tool stations No. 4 and No. 5, may be governed by a common attachment-operating mechanism 85 comprising an inner stop or trip rod 35, a

from the tube 37 to the respective spindles 16-17 may include axially overlapping parts clamped as by means 86-86 to the feed tube 37. The axial overlap may be achieved by cutting away an asymmetrical part of the clamping portion of the yoke 49 in the region of attachment to the feed tube 37. Both members 49' may be duplicates of each other, and when clamped as illustrated in Fig. need involve no greater axial-length requirements than the single yokes 49 described in connection with Figs. 3 and 4.

A single clamp 54' carried by the feed tube 37 may, in conjunction with the threaded means 80 (engaging boss 87), provide for the simultaneous relative axial adjustment of the feed tube 37 and a selected one of the spindles 16-17. For conservation of overall axiallength requirements, the same clamp54' may also serve for effecting small axial adjustment of the yoke 49f for spindle 16; thus, a second threaded means 80' maybe carried on another part of clamp 54 and may independently adjustably engage boss 87', as will be clear.

It will be appreciated that the described dual control from a single feed tube 37 lends itself particularly to a machine operated with double indexing, namely, duplicate operations for each of two adjacent spindles, and double indexing between operations. The symmetrical placement of each feed tube 37 with respect to the spindles adjacent thereto makes for ready set up at the two spindles at which duplicate operations are to be performed.

It will be seen that I have described an exceedingly simple attachment-operating mechanism featuring versatility in application, without requiring removal in order to serve a selected one or both of two adjacent spindles. Also, with relatively little additional effort the entire mechanism may be removed as a unit and placed in any other desired operating position, thus serving any one of all the working stations on a multiple-station machine. By providing my mechanism as a unit-handling device, I not only simplify set-up operations, and therefore reduce down time between the filling of successive shop orders, but I also provide fewer encumbrances in the working area of the machine, thus simplifying the problem of chip removal. Further, I have provided my mechanism with a thoroughly concealed and wellprotected stop which cannot in any way become obstructed with chips or foreign matter. and which will therefore maintain an accurate stop limit once the desired adjustments have been made. These adjustments may be made by simple operations within the working area and requiring no entrance into the power case.

While I have described my invention in detail for the preferred forms shown, it will be understood that modifications may be made within the scope of the invention as defined in the claims which follow.

I claim:

1. In an attachment-operating mechanism of the character indicated, three mutually supporting elongated members slidable longitudinally with respect to each other, cooperating abutment means on two adjacent of said members for providing a limit of relative longitudinal feed of said two adjacent members with respect to each other, means for fixedly mounting one of said two adjacent members to a machine frame, feed-thrust means carried by the remaining of said three members for translating feed thrusts from a driving member to a driven member, and connecting means between said remaining member and the other of said two adjacent members.

2. In an attachment-operating device of the character indicated, three concentric relatively axially movable elongated members, cooperating abutments on two of said members for limiting one direction of axial movement of said two members with respect to each other, means for fixedly mounting one of said two members, control-connection means between the other of said two members and the remaining of the said three members, feed means for said remaining member, and means including a threading tool connected to both said other of said two members and said remaining member.

3. In a tool-operating device, three concentric relatively axially movable elongated members, cooperating abutments on two of said members for limiting one di-.

rection of axial movement of said two members with respect to each other, means for fixedly mounting one of said two members, control-connection means including means threadedly interconnecting corresponding threaded ends of the other of said two members and of the remaining of said three members, feed means for said other of said two members, and a tool connected to one of said threadedly interconnected members.

4. A mechanism according to claim 3, in which the radially outer of said threaded members has a threaded bore and the radially inner of said threaded members is externally threaded, said control-connection means further including a bushing threadedly connecting both said members.

5. A mechanism according to claim 4, in which the inner of said members is threaded entirely through said bushing and projects externally therebeyond, whereby angular threaded adjustment of said inner member within said bushing and therefore with respect to said outer member may be made adjacent said bushing.

6. In an attachment-operating mechanism of the character indicated, an elongated frame-reference tube including a mounting flange at one end thereof, a feed tube slidably guided by said frame-reference tube and externally thereof, and an internal rod slidably guided within said frame-reference tube, cooperating abutments Within said frame-reference tube and cooperating between said rod and said frame-reference tube to determine a limit in one direction of relative axial movement between said rod and said frame-reference tube, and means including a tool connected to both said feed tube and said internal rod.

7. In combination, a frame, a tool spindle journalled in said frame, a tool carried by saidspindle and including a part axially movable relative to said spindle, and a single unitary actuating mechanism for said spindle and for said part; said mechanism comprising three elongated mutually supporting concentric members, securing means attaching the intermediate of said members rigidly to said frame, cooperating abutments between said intermediate member and the inner of said members for determining a forward limit of relative movement of said inner and intermediate members, a control connection from said inner member to said tool part,

i and a feed-thrust connection from the outer of said mem bers to said spindle.

8. The combination of claim 7, in which said feedthrust connection includes an axially resilient element.

9. The combination of claim 7, in which the connection between said inner member and said tool part includes an abutment aligned with the projecting end of said intermediate member, whereby, upon retraction of said outer member and therefore of the spindle and tool, said abutment may be intercepted by said intermediate member, as for resetting the tool carried by said spindle.

10. The combination of claim 7, and including shockabsorbing means axially between said securing means on said intermediate member and the corresponding end of said outer member.

11. In combination, a tool spindle and a single unitary actuating mechanism therefor, said mechanism comprising three concentric relatively slidable members, cooperating abutment means between the intermediate of said members and said inner member for limiting one direction of relative movement of said inner and interme- 9 diate members, frame-mounting means for rigidly mounting said intermediate member, a feed-thrust connection between the outer of said members and said spindle, and removable means rigidly interconnecting the outer projecting ends of said inner and outer members independently of said intermediate member.

12. In a multiple-spindle machine of the character indicated, frame means, two tool spindles journalled in said frame means at adjacent spindle positions, and a common unitary attachment-operating mechanism symmetrically disposed between said spindles, said mechanism comprising three concentric mutually supporting elongated relatively axially movable members, the common axis of said members being equidistant from the axes of both said spindles, one of said members being rigidly attached to said frame means, cooperating abutment means between said one member and another of said members for limiting one direction of relative axial travel of said one and said other member, a feed-thrust connection selectively connectable between the third of said members and one or the other of said tool spindles, and means including a threading tool on one of said spindles and connected to said third member and to said other member.

13. The combination of claim 12, and including a second feed-thrust connection between said third member and the otherwise unconnected one of said spindles.

14. The combination of claim 13, in which said feedthrust connections include axially overlapping elements clamped to said third member.

15. In a device of the character described, a tool spindle, axial driving means connected to said toollspindle, support means for said driving means including an abutment, stop means for limiting the movement of said driving means, a connecting member between said stop means and driving means; said driving means, support means, and stop means being coaxial with each other and parallel to the axis of said tool spindle.

16. In a device of the character described, a tool spindle, a driving member, means for adjustably connecting said driving means in reciprocable driving relation with said tool spindle, support means for said driving member, an abutment on said support member, a stop member coacting with said abutment for limiting the movement of said driving member; said driving member, support member and stop member being mounted coaxially with each other and parallel to said tool spindle.

17. A device as in claim 16, and an extension removably connected to said stop member, said removable member coacting With said support member to permit relative limited motion between said stop member and said driving member.

18. A device as in claim 16, and removable means for adjustably locking said stop member to said driving member.

19. A mechanism according to claim 1, in which said connecting means includes a lost-motion connection.

20. A mechanism according to claim 19, in which said lost-motion connection includes a resettable die having two relatively movable actuation parts, one of said parts being connected to said remaining member, and the other of said parts being connected to said other adjacent member.

21. A mechanism according to claim 1, in which said connecting means includes a removable connecting element at one longitudinal end of said mechanism directly connecting said remaining member to said other adjacent member.

22. A mechanism according to claim 6, in which said threading tool is of the resettable variety including a body and an actuator element, said body being connected to said feed tube, and said actuator element being connected to said rod.

23. A mechanism according to claim 6, in which said tool is fixedly connected to said feed tube, and means directly connecting an end of said feed tube to the corresponding end of said rod.

References Cited in the file of this patent UNITED STATES PATENTS 

